I can't really comment on what's causing this since I haven't imported into a dashboard. But I have to import data on a monthly basis and I created a survey shell with embedded data for each field, and import data into that survey through data & analysis tab. And mapped that survey into the dashboard.
I believe you can also create and imported data project instead as well as an alternative.

Thanks for your answer InessaG .
I have tried as you told me but it is still not working.
After create the embedded data and import my data :
Not able to retrieve my fields in Results

It's difficult to troubleshoot this without being able to play around with mapping and widgets. I suggest you reach out to support.

Hi ava005!
I believe it's because your fields are Text Value and Numeric Value. The simple chart is compatible with Text Sets and Numeric Sets: https://www.qualtrics.com/support/vocalize/widgets/chart-widgets/simple-chart-widget/?parent=p00734
You can change the field type in mapping by clicking on the field type name.
Hope that helps!
Carrie